A part of Afghanistan not known for seismic activity was struck by an 'unprecedented' number of big earthquakes this week and no one knows when they'll end, an expert says

• Western Afghanistan has been struck by four major earthquakes in just over a week.
• A researcher with the US Geological Survey said these earthquakes are "unprecedented."
• Unsure when they'll end, Afghan residents are living in tents to avoid collapsing buildings.

Western Afghanistan was struck by yet another powerful earthquake on Sunday, its fourth in just over a week.